Prior to setting forth a short discussion of the related art, it may be helpful to set forth definitions of certain terms that will be used hereinafter.
The term “vehicle” as used herein, is defined as a mobile machine that transports passengers or cargo. Vehicles that do not travel on land include watercraft, aircraft and spacecraft and are also included in vehicle as defined herein. In some embodiments, a vehicle may also include a platform which is even a more generalized term defined as any object, either stationary or in motion, to which a payload such as a satellite communication system, may be mounted.
The term “reception quality parameters” as used herein, is defined as quantitative indicators of the ability of a channel to convey data over a communication link.
The term “received signal strength indicator” (RSSI) as used herein, is a measurement of the power present in a received radio signal.
The term “equivalent isotropically radiated power” (EIRP) is the amount of power that a theoretical isotropic antenna (which evenly distributes power in all directions) would emit to produce the peak power density observed in the direction of maximum antenna gain. EIRP can take into account the losses in transmission line and connectors and includes the gain of the antenna. The EIRP is often stated in terms of decibels over a reference power emitted by an isotropic radiator with equivalent signal strength. The EIRP allows comparisons between different emitters regardless of type, size or form.
The term “line of sight (LOS) blockage” as used herein, is any scenario in which a degradation of the reception quality parameters goes below a predefined level that results in at least partial blockage of the data transfer or even a full blockage thereof.
The term “mobility parameters” as used herein may include, position, orientation and velocity and any derivative thereof of a platform or a satellite.
The term “rerouting” or as used herein relates both to rerouting in the network level and in the physical level and may include any change of the path of a communication between a two nodes in a communication network. Rerouting in the network level may include any change of the flow of data from one node to another via different nodes. In the physical level, rerouting relates to a spatial change of the communication link, usually from the transmit antenna to the receive antenna, wherein the communication link may include relays along the path.
LOS blockage is a main reason for degradation of satellite communication (typically a geostationary satellite). Any vehicle-mounted satellite communication system is dependent upon a clear LOS with the communication satellite. While addressing LOS blockage in real time is known in the art, predicting LOS blockage and tailoring the appropriate remedy for the specific type of LOS blockage has not yet addressed. It would be therefore advantageous to provide a method that will enable to use alternative satellite communication links whenever such a blockage is predicted.